1. Field of the Invention
The present invention relates to a method of cleaning a solid surface and, in particular, to a method of cleaning a solid surface in which fine frozen particles are produced and then sprayed onto the surface of a solid, such as a semiconductor wafer or reticle printed board or the like, in order to remove contaminants deposited on the solid surface.
2. Description of the Related Art
FIGS. 1 and 2 are views for explaining this type of conventional cleaning method which is applied to a general degreasing cleaning or a general cleaning as a substitution for trichloroethylene cleaning, freon cleaning or the like. To remove contaminants deposited on the surface of a solid such as a semiconductor wafer, super pure water is jetted onto the surface, a solid 2 to be cleaned from a jet nozzle 1 at a high pressure of 30 Kg/cm.sup.2.G or greater, as shown in FIG. 1. Thus, a contaminant 3 is removed from the surface of the solid 2. As shown in FIG. 2, the contaminant 3 is also sometimes removed from the surface of the solid 2 by super pure water which is sprayed onto the surface of the solid 2 to be cleaned, from the jet nozzle 1, and at the same time a cylindrical brush 5 having a rotational axis 4 rotates in the direction of an arrow A and slides in the direction of an arrow B with contact to the surface of the solid 2.
As described above, a conventional method of cleaning a solid surface has been performed by the use of the pressure of a liquid such as jetted super pure water, and frictional force made by a brush. However, the conventional method of cleaning a solid surface has the following problems. As contaminants become very fine (particle size: 10 .mu.m or smaller), the sticking force of the contaminants to the surface of a solid to be cleaned increases, and the force of a usual jetting of a liquid to remove such fine contaminants is too weak, and thus the cleaning effect (or a removal effect) is insufficient. If the liquid jetting pressure is increased (100 Kg/cm.sup.2.G or greater), a part of the inner side of the jet nozzle is worn away due to the flowing of the liquid against it. This worn away part is jetted together with the liquid, causing the surface of a solid to be contaminated. If a brush is used, there is a danger that the surface to be cleaned will be contaminated due to the wearing of the brush, and that contaminants attached to the brush, which is removed from the surface of a solid, will be deposited again onto the surface of a solid to be cleaned.